The criminal destruction of life by poison has been practised from ancient times. Very little was known of toxicology in those days, and even the symptoms often passed unrecognised or were attributed to natural causes, and the poisoners' fiendish work was frequently undiscovered and rendered easy. In the early Christian era, poisoning, indeed, became quite a profession, and convenient individuals could be hired with little difficulty to administer a deadly dose to an enemy or rival. Agrippina, in refusing to eat some apples offered to her at table by her father-in-law Tiberius, must have had suspicions of this kind. Locusta, who is said to have supplied the poison by which Agrippina got rid of Claudius, and who also prepared the dose for Britannicus, according to the order of his brother Nero, is the first professional poisoner of whom we have record.

In the year B.C. 331 an epidemic broke out in Rome which was supposed to proceed from corrupt air, but it was observed that the principal patricians only were the victims. Their deaths, however, were attributed to infection, for poisoning was then scarcely known in Rome nor was there a law for its punishment. In the general grief, a female slave presented herself to the edile curule Q. Fabius and accused more than twenty Roman ladies of poisoning: designing specially Cornelia, a lady of an illustrious family of that name, and Sergia, another patrician lady. It is recorded that as many as three hundred and sixty-six ladies were similarly accused; but Cornelia and Sergia were detected in compounding their fatal potions. "When led before the popular assembly they maintained their preparations were harmless remedies. The slave, seeing herself accused as a false witness, asked that the ladies should be required to swallow their own potions; which they did, and by so doing avoided a more shameful death."

Later, there were, doubtless, many, both men and women of the baser sort, who professed to practise alchemy, and had dealings in the black arts, who for suitable consideration would procure poison for criminal purposes. In mediæval times a law was passed in Italy rendering the apothecary, who knowingly sold poison for criminal purposes, liable to a heavy penalty, and yet secret poisoning was practised to a very large extent; and there were probably many like the poor apothecary of Mantua in Romeo and Juliet, who, in response to Romeo's demand for poison, replied, "My poverty and not my will consents."

From the fifteenth to the seventeenth century two great criminal schools arose in Venice and Italy.

The Venetian poisoners who first came into notoriety, flourished in the fifteenth century. At that period the mania for poisoning had risen to such a height, that the governments of the states were formally recognizing secret assassination by poison, and considering the removal of emperors, princes, and powerful nobles by this method. The notorious Council of Ten met to consider such plans, and an account and record of their proceedings still exists, giving the number of those who voted for and who voted against the proposed removal, the reasons for the assassination, and the sum to be paid for its execution. Thus these conspirators quietly arranged to take the lives of many prominent individuals; and when the deed was executed, it was registered on the margin of their official record by the significant word "Factum." On December 15, 1543, John of Raguba, a Franciscan brother, offered the Council a selection of poisons, and declared himself ready to remove any person whom they deemed objectionable out of the way. He calmly stated his terms, which for the first successful case were to be a pension of 1,500 ducats a year, to be increased on the execution of future services. The Presidents, Guolando Duoda and Pietro Guiarini, placed this matter before the Council on January 4, 1544, and on a division, it was resolved to accept this patriotic offer, and to experiment first on the Emperor Maximilian. John, who had evidently reduced poisoning to a fine art, submitted afterwards a regular graduated tariff to the Council, which ran as follows—

He further adds at the foot of the document, "The farther the journey, the more eminent the man, the more it is necessary to reward the toil and hardships undertaken, and the heavier must be the payment."

The school of Italian poisoners became prominent in the sixteenth and seventeenth centuries, and the magnitude of their operations during that period struck terror into the hearts of the chief nobles and rulers of that country.

The mania for secret poisoning seems to have seized on all classes from the highest to the lowest, and no one who made an enemy was safe. Porta, in his work published in 1589, gives some account of the poisons used at the time, and seems to have made a study of the subject. He describes methods for drugging wine (a favourite medium of administration) with belladonna root, and also mentions nux vomica, aconite, and hellebore, in his account of poisonous bodies. He gives the following recipe for compounding a very strong poison, which he calls "Venenum Lupinum": "Take of the powdered leaves of Aconitum lycoctonum, Taxus baccata, with powdered glass, caustic lime, sulphide of arsenic, and bitter almonds. Mix them with honey, and make into pills the size of a hazel nut." He also recommends a curious mixture to poison a sleeping person. It is composed of a mixture of hemlock juice, bruised stramonium, belladonna, and opium. This is to be placed in a leaden box with a perfectly fitting cover, and allowed to ferment for several days; it is then to be opened under the nose of the intended victim while asleep. So long as the individual only got the smell and did not swallow the compound, it certainly would not do him much harm.

The most notorious of the Italian poisoners was the woman Toffana or Toffania, who carried on her practices from the latter end of the seventeenth century until she was brought to justice in 1709. Toffana resided first at Palermo, but removed to Naples in 1659 during the pontificate of Alexander VII. This later Circe gained large sums of money by the sale of certain mysterious preparations she compounded, which were afterwards proved to be simply solutions of arsenious acid. These were circulated throughout Italy in small glass phials, bearing the image of a saint, and labelled various names such as "Acquetta di Napoli," or the "Manna of St. Nicholas of Bari," and "Aqua Toffana." Any one in the secret could buy the poison for its supposed use as a cosmetic, or other innocent property, and then employ it for any purpose they wished. This infamous woman carried on her nefarious trade from girlhood until she was nearly seventy years of age, without ever having fallen into the meshes of the law, and it is stated over six hundred persons were poisoned through her instrumentality. She dealt only with individuals, after due safeguards had been built up, and she changed her abode so frequently, and adopted so many disguises, that her detection was rendered very difficult. She also called in the aids of religion and superstition, and those who were uninitiated in the history of her deadly elixir, imagined it to be a certain miraculous oil which was supposed to ooze from the tomb of St. Nicholas. The Popes Pius III and Clement XIV are said to have fallen victims to its use. The composition of the Acquetta di Napoli was long a profound secret, but it is said to have been known by the Emperor Charles VI of Austria. According to a letter addressed to Hoffmann[2] by Garceli, physician to the emperor, he informed the latter that, being Governor of Naples at the time that the Acquetta was the dread of every noble family in the city, and when the subject was investigated legally he had an opportunity of examining all the documents, and that he found the poison consisted of a solution of arsenic in Aqua cymbalariæ. The dose was said to be from four to six drops in water, and that it was colourless, transparent and tasteless. When the manufacture and sale of the poison was at last traced to Toffana, she took refuge in a convent, from which the abbess and archbishop refused to give her up, and so continued to sell the water for twenty years longer, and evaded punishment for the time. Public indignation was roused to such a pitch, that at last the convent was broken into by a body of soldiers, who secured Toffana and handed her over to the authorities. She was tortured until she confessed in 1709, and then strangled, her body being thrown into the garden of the convent which had sheltered her.